A method of generating a three-dimensional (3D) video content based on a two-dimensional (2D) video (still image or moving picture) content has been proposed. This method generates parallax images for stereoscopic viewing from 2D images included in the 2D video content using depth maps. Each depth map specifies depth values assigned to respective pixels of a 2D image. The depth maps may be automatically estimated from the 2D images or may be manually created. Parallax amounts of respective pixels can be uniquely derived from depth values according to a geometric relationship. This method generates parallax images by warping respective pixels of the 2D images according to their parallax amounts.
Furthermore, a method of adjusting the strength of the stereoscopic effect of a 3D video content (that is, broadening or narrowing down the dynamic range of depth values) has also been proposed. When the stereoscopic effect is emphasized, the 3D video content becomes more powerful. When the stereoscopic effect is suppressed, user's fatigue as a result of viewing of the 3D video content can be reduced. This method estimates depth maps of 3D images included in the 3D video contents by, for example, stereo matching. This method creates parallax images after desired adjustment is applied to the estimated depth maps.
The estimated depth maps may include errors. For example, background depth values may be assigned to foreground pixels, or foreground depth values may be assigned to background pixels. When such estimation errors occur in the vicinity of a boundary (for example, an object contour) between a foreground and background, parallax images including boundary lines which suffer jaggies between the foreground and background are created, thus deteriorating the quality of 3D images. As for the possibility of errors included in depth values, the same applies to the case in which the depth maps are manually created.